Electroplating method



May 23, 1933. w. BELKE 1,910,145

ELEGTROPLATING METHOD Filed Dec. 11, 1930 2 Sheets-Sheet l .May 23,1933. W E BELKE 1,310,145

ELECTROPLATING METHOD Filed Dec. 11, 1930 2 Sheets-Sheet 2 efficiencyand the desirability of an electroplating apparatus or machine of-thispar-' Patented May 23," 1933 WILLIAM E. BELKE, OF CHICAGO, ILLINOISELEGTROI'LATING METHOD Application filed December 11, 1980. Serial No.501,546.

This invention relates to electroplating apparatus in general, and moreespecially to apparatus of this kind which 1s adapted for chromiumplating.

Generally stated, the object of the invention is to provide a novel andimproved construction and arrangement, in a plating machine orapparatus, whereby centrifugal force is utilized to insure effectivecontact between the cathode and the metal article to be plated. This isadvantageous for platin chromium plating, inasmuch as for this purpose aheavier current is required, and hence a more positive and reliablecontact is required between the cathode and the object or article to beplated.

It is also an object to provide certain details and features ofconstruction and combinations tending to increase the general ticularcharacter.

To the foregoing and other useful ends, the invention consists in thematters hereinafter set forth and claimed, and .shown in theaccompanying drawings, in which,-

Fig. 1 is a side elevation, tions in vertical section, machine embodyingthe vent-ion.

Fig. 2 is a plan of said machine.

Fig. 3 is an enlarged fragmentary detail sectional view.

with certain porof an electroplating principles of the inline 4 4 inFig. 1 of the drawings.

As thus illustrated, the invention comprises body frames or castings 1and 2 of any suitable character, provided at their upper ends withbearings 3 in which are mounted the trunnions 4; that are rigid with thetilting frame 5, the latter being preferably U-shaped in form, andprovided at its lower side with-a downward extension 6, as shown.

The barrel or container 7 has its bottom provided with a stem 8 in theform of a vertical shaft, and this shaft is coupled to an electric motor9 that is mounted on the extension 6 previously mentioned. In this way,by operating said motor, the barrel 7 mg in general, but is especiallyadvantageous previously described. Fig. 4 is an enlarged horizontalsection on shown in is rotated about a vertical axis. This barrelpreferably has a separable top 10 held in place by bolts 11, and the topplate 12 is removably fastened to said top section 10 by means of boltsor screws 13, as shown. The inner surface of the barrel has aninsulating lining 14, of any suitable character, and the middle portionof the barrel is provided interiorly with a mesh-like band 15electro-conductively connected to the barrel by screws 16, 'or by anysuitable means. The lower conical or hopper-like portion of the barrelis provided internally with ribs 17, for a purpose that will hereinaftermore fully appear.

The anode 18 is of any suitable metal. If nickel or silver plating isto'be done, this anode can be of the required metal for that purpose.However, for chromium plating, the desired metal is in the solution, noton 7 the anode, and for such kind of platingthe said 'anode may be ofany metal commonly or advantageously-employed for this purpose. It.will'be understood, furthermore, that in chromium plating, a muchheavier current is necessary, in order to plate the metal in solution onto the object to be plated. As shown, the anode 18 is preferablysupported on thelower'end of a stem 19, which latter is' removablysecured at 20 in the middle portion of the bar 21, the ends of thelatter being secured by bolts 22 to the upper ends of the U-shap'ed bodyframe 5 The bolts 22 may be insulation 23, in the' manner 5 ig. 3 of thedrawings, whereby the bar 21 will be insulated from the U-shaped bodyframe 5, while the barrel 7 is electrieallyconnected with said U-shapedframe, the latter having a negative electrode or connection 24, and theanode having a positive electrode or, connection 25 that is fastened inany suitable. manner to the said bar 21 that supports the anode.

In use, the articles, if they are comparatively small ones, to be platedcan be inserted through the opening 26 in the plate or cover 12 ofinsulation, and thus dropped into the solution within the rotary barrel.Upon starting the motor 9, the barrel will insulated b band 15, but indifferent positions from rotate and throw the articles upwardly andbetween the articles and the band will be sufiicient and effective forthe electric current necessary, such as the heavy current ordinarilyemployed in chromium plating. By stopping the motor 9, the articles orobjects to be plated will be permitted to fall down into the lowerportion of the barrel, and then when the motor is started again, thesearticles will be thrown out against the what they were before. Byrepeating this from time to time, it will be seen that the articles orobjects to be plated will be turned over and around, and exposed atdifferent sides in the direction of the anode 18, where, by all sides ofsaid objects or articles will be suitably plated, and whereby theplating will not be defective because of the contact between the objectsor articles themselves when a greater or less number of them is placedin the barrel. In other words, the' apparatus or machine can be operatedin a manner to keep the said articles or objects in proper position forplating, by turning them over or around, now and then, inasmuch as thearticles or objects to be plated are maintained in position bycentrifugal force, instead of by gravity or other expedients.

It will be readily understood that the invention is not limited to theexact construction or method shown and described, in order to utilizecentrifugal force as the means for maintaining contact between thecathode and the articles or objects to be plated. The

, construction and mode of operation shown and described areillustrative of an operative form of the invention, but it is obviousthat modifications or equivalent arrangements can be employed, toutilize centrifugal force for the purpose described, without departingfromvthe spirit of the invention. For example, for some purposes, it maylie found desirable to omit the insulation on the inner surface of thebarrel or rotary container, depending upon circumstances and thecharacter of the plating to be done. Again, while the drawings show amotor 9 that can be started and stopped to accomplish the desired modeof operation, as explained, it is obvious that the starting and stoppingof the rotary barrel can be produced in any suitable or\ desired manner,all within the scope of the invention, in order to periodically readjustor change the positions of the articles or objects to be: plated.Moreover, as shown, the outer barrel forms, the cathode, and the anodeis stationary, but there are obvious modifications of this, for thepurpose of utilizing centrifugal force to maintain relatively heavypressure contact between the cathode and the articles or objects to beplated, and hence the invention is not limited to having the cathoderotate while the anode remains stationary.

As stated, heavy current is necessary, as well as relatively heavycontact pressure, for some kinds of plating, as, for, example, chromiumplating, and such plating must be done rapidly and skilfully in order toinsure a uniform and attractive, surface for the article when theplating is finished. The invention, of which the accompanying drawingsare illustrative of an operative form thereof, is calculated to insurethe requirements and conditions necessary for effective plating.

It will be understood that the opening 26 can be provided with asuitable closure, not shown, to-avoid any ossible discharge of thesolution during h gh-speed rotation of the receptacle forming thebarrel. To discharge the plated articles from the barrel,

shaft 4, can be rotated to tilt the frame 5 about a horizontal axis, inorder to turn the barrel upside down and thus discharge the contents.For this purpose, the cover 12 can be removed, and even the bar 21 canalso be removed, to facilitate the discharge of the plated articles fromthetop or mouth of the barrel. Thedrawings are thus illustrative of onemethod of embodying and using the invention in an operative machine. Itwill also be understood that the motor 9 may have any suitable means,such as an ordinary switch, not shown, for starting and stopping it inthe desired manner. It will be understood, of course, that to re-adjustthe articles or objects that are being plated it is not necessary toabsolutely stop the machine, as any change in the speed of rotation, asby accelerating the speed suddenly, or by retarding it, will accomplishthe desired purpose.

Furthermore, it will be seen that the container or barrel is tapereddownwardly and upwardly, so that its middle portion is of largerdiameter than its upper end or its lower end. In this way, when thebarrel or container is rotating at the desired speed, centrifugal forcewill cause thesolution to hug the inner surface of the middle portactwith a cathode, while keeping the plating solution in ring form in thezone occupied by the articles being plated, with the cathode forming theperiphery of said ring, and with upwardly and downwardly tapering spacemaintained above and below said ring.

2. A method as specified in claim 1, the centrifugal force beingdeveloped by rotation of the cathode about a vertically disposed axis,whereby said pressure contact is uniform at all sides of said axis.

3. A method as specified in claim 1, in-

' volving the periodic tumbling of the articles away from the cathode,by gravity, and rcassembling the articles in different positions againstthe cathode, whereby to periodically change the positions of thearticles to inslle uniform plating on the surfaces there- 0 4. A methodas specified in claim 1, comprising the maintaining of an electriccurrent of sufficient strength for chromium plating from the anodethrough the solution to the articles and cathode, while maintaining saidpressure contact suificiently to insure efi'ective chromium plating.

Specification signed this 6th day of De cember, 1930.

WILLIAM E. BELKE.

